A woman has recalled that was the dishevelled and "hysterical" state her friend was in the night she was allegedly raped by a stranger in Hyde Park, in Sydney's CBD, in August 2013.

Joseph Stephen Rosenburg, 51, has pleaded not guilty to three charges of sexual intercourse without consent and three counts of indecent assault upon the 18-year-old woman and is on trial in the Downing Centre District Court.

On Wednesday, a friend of the alleged victim said she called the teenager that night after getting a worrying text message from her.

The alleged victim said she was out in the city and didn't know where she was, so the friend suggested she "stay in the light" and find a street sign. The friend then drove from her home in Sydney's south-west to the city to pick her up.

The court heard that during the trip to the city, the friend talked to the teenager on the phone.

"She was hysterical, just crying. She was crying and saying 'he hurt me, he hurt me,' and I said 'what do you mean?' and she said 'He raped me' and then was just crying." the friend, who cannot be identified, told the court.

When the friend found the alleged victim waiting outside St James railway station in the early hours of August 30, she was "lying in a ball".

"She was just crying hysterically, couldn't breathe much, her hair was messy, she smelled of vomit and did not look good at all," the friend said.

"[There were] leaves stuck in her hair and on her back."

The friend said the alleged victim was upset when she got in the car, as they drove towards a hospital.

"When she first saw me ... she reached and grabbed my arm and didn't want to let go."

The pair then went to hospital, where the alleged victim remained in "hysterics" and didn't want to talk to medical staff, the court was told.

The jury has previously heard that the alleged victim was heavily affected by alcohol and had been vomiting when she laid down near a building across from Hyde Park.

Mr Rosenburg is accused of approaching her and reaching up her dress, before following her into the park and allegedly raping her.

Under cross-examination from Mr Rosenburg's barrister, Ken Averre, the friend said the alleged victim was coherent during the phone calls and the friend could understand everything that was said.

Another friend told the court that the alleged victim drank about a quarter of a bottle of vodka in less than 15 minutes earlier in the night.

Crown prosecutor Craig Patrick has previously told the court that DNA found on the woman's underwear and her body matched the profile of Mr Rosenburg

Mr Averre said there would be no dispute that the DNA belonged to Mr Rosenburg, but that consent would be an issue.

The trial continues before Judge Stephen Hanley.